Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 15 Dec 2014

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

6(4)

18(18)

33(-)

19(8)

0.2(2)

9(40)

South

4(2)

18(18)

5(-)

15(6)

0.4(4)

9(36)

East

7(4)

18(18)

23(-)

20(9)

0.3(3)

11(47)

West

4(2)

17(17)

8(-)

19(8)

0.4(4)

8(34)

Central

12(7)

15(15)

21(-)

24(10)

0.5(5)

7(29)

1-hr PM2.5 (µg/m3)b Readings on 15 Dec 2014

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

9

5

8

13

8

10

7

3

8

12

21

18

South

6

6

7

3

6

5

8

8

6

7

22

16

East

11

13

23

14

15

15

15

15

12

18

18

12

West

12

10

12

5

7

9

6

4

5

4

10

16

Central

4

9

5

5

5

9

10

8

6

4

8

10

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

15

9

10

9

10

5

8

7

8

4

11

-

South

21

17

8

17

6

3

2

7

17

5

3

-

East

7

10

7

9

5

3

6

7

7

8

9

-

West

10

11

6

9

8

6

8

8

6

12

5

-

Central

10

8

7

11

7

4

5

5

8

9

4

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
15 Dec 2014

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

33

34

39

38

37

35

37

36

34

34

45

52

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

53

52

43

41

35

31

24

23

30

33

33

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.